The overarching goal of the proposed study is to improve communication among clinicians, patients, and family caregivers about a diagnosis of dementia. Specific aims. 1) Characterize physician, patient, and companion behaviors during a dementia diagnosis disclosure encounter, using standardized interaction analysis systems. 2) Identify features of the diagnostic disclosure encounter that predict subsequent depression, anxiety, satisfaction, and diagnostic comprehension in patients and companions. 3) Compare features of the diagnostic disclosure encounter across different levels of patient dementia severity. Design and methods. 90 videotapes of diagnostic disclosures were collected as part of another study. In the current study these videotapes will be coded using two standardized interaction analysis systems. Physician, patient, and companion behaviors from the coded interactions will be used to predict subsequent patient and companion psychological distress, satisfaction, and diagnostic comprehension. Rationale. Results from this project can guide the development of empirically-based clinical practice guidelines and educational materials for physicians, patients, and family members to help them have productive conversations about a dementia diagnosis. These conversations are essential to short-term and long-term psychological adjustment and practical adaptation to the demands of the disease. Health relatedness/Relevance to agency. This project will generate basic empirical data regarding triadic healthcare interactions, with clinical implications for the ways in which clinicians and healthcare consumers talk about dementia. Thus, the project is the type of applied science that fulfills the mission of the National Institute on Aging to improve the health and well-being of older adults. PUBLIC HEALTH RELEVANCE: Relevance to public health. When physicians tell patients and family members about a dementia diagnosis, the conversation needs to be emotionally supportive but also clear about the facts. Results from this study will suggest effective ways to talk about a dementia diagnosis. The goal is to help patients and family members understand what the diagnosis means so that they can make informed decisions about next steps in managing the disease.